global max_rows option for print method

[jgabry]

closes #469

Submission Checklist

• Run unit tests
• Declare copyright holder and agree to license (see below)

Summary

Allows options(cmdstanr_max_rows = value) to set max_rows argument of print method for an entire R session (or until changing the option).

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(this will be you or your assignee, such as a university or company):
Columbia University

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• Code: BSD 3-clause (https://opensource.org/licenses/BSD-3-Clause)

[codecov-io]

Codecov Report

Merging #470 (51fb1cd) into master (053a1ec) will decrease coverage by 1.88%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #470      +/-   ##
==========================================
- Coverage   93.42%   91.54%   -1.89%     
==========================================
  Files          12       12              
  Lines        2861     2861              
==========================================
- Hits         2673     2619      -54     
- Misses        188      242      +54     

Impacted Files	Coverage Δ
R/fit.R	98.42% <100.00%> (ø)
R/install.R	61.56% <0.00%> (-10.63%)	⬇️
R/run.R	95.30% <0.00%> (-1.51%)	⬇️
R/utils.R	90.54% <0.00%> (-1.36%)	⬇️
R/model.R	91.12% <0.00%> (-1.17%)	⬇️
R/csv.R	98.16% <0.00%> (-1.05%)	⬇️

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[rok-cesnovar]

Looks good. One suggestion or rather an idea. Maybe we go with the name

cmdstanr.max_rows

I know brms uses options like brms.normalize and such. You are obviously the R packages expert here so you would know better than me what is more common.

[jgabry]

Yeah I've seen both conventions used. I don't have a strong preference, I just used cmdstanr_max_rows to be consistent with the cmdstanr_verbose option that we already have.

[rok-cesnovar]

Cool, if both are common then lets merge this.